Somali pirates tonight demanded a ransom payment of $7m (£4.2m) for the safe return of a British couple who they kidnapped a week ago.

In a phone call translated by the BBC, one of the pirates said: "If they do not harm us, we will not harm them – we only need a little amount of seven million dollars."

A Foreign Office spokesman said tonight: "Hostage taking is never justified. Paul and Rachel are blameless tourists. They should be released immediately and unconditionally."

"The government will not make substantive concessions to hostage takers, including the payment of ransoms."

Earlier today, Rachel Chandler, who is being held by the pirates with her husband Paul, made contact with her relatives for the first time since the couple were seized.

She told her brother Stephen Collett she was "bearing up" and added: "Please do not worry about us. We are managing."

The phone call was broadcast on ITV News , a day after her husband made first contact with the outside world via the broadcaster.

Rachel Chandler, 55, broke down during the call despite repeatedly reassuring her brother she was being well cared for.

"I'm bearing up. Thank you for everything you are doing," she said. "Thank you, thank you very much."

Her voice cracked but she managed to compose herself as the conversation continued. "We are safe," she said. "If we want anything they will provide it. They are very hospitable people."

ITV News spoke to Paul Chandler yesterday but in a call he sounded much more strained and he seemed to be speaking deliberately slowly.

Collett asked his brother-in-law if he was being well looked after. He replied: "So far, yes." Told that the family was trying to secure their release, Paul Chandler said: "We know nothing here. It is nice to speak to you."

Although Rachel Chandler did not say where she was, it is thought the pirates who attacked the yacht, the Lynn Rival, last Friday may have moved their captives to sea to thwart any rescue attempts.

Speaking to ITV News, Paul Chandler, 59, said he and his wife, from Tunbridge Wells, Kent, were being held on the Kota Wajar, a container ship hijacked in the Indian Ocean on 15 October.

Local fishermen reported seeing the couple being taken to the village of Ceel Huur near the pirate stronghold of Harardhere.

A spokesman for the pirates, who identified himself only by his first name, Abdinor, said the couple would be moved to a ship anchored off the coast of Somalia. He said it would be safer for the couple to be kept on a ship with other hostages.

The man said the Chandlers were healthy and that the pirates took them to rest on land at Harardhere last night. The group was yet to make a ransom demand, he said.

In a phone call with BBC News, Paul Chandler was clearly unable to speak freely. When asked if he was in Somalia, he said: "I can't answer that."

Whitehall staff met at the Cobra emergency briefing room again amid reports that the kidnappers were about to make their ransom demands.

A Foreign Office spokesman said a government team was working to secure the couple's release but added that the meeting was not a full Cobra meeting and that no ministers attended.